Trustees are elected by the parent community, staff members and, in the case of schools with students above Year 9, the students. The principal is also a member of the board. The board can also co-opt additional trustees. Co-option cannot be used to fill casual vacancies on a board; a board must hold a by-election to fill the casual vacancy or fill the casual vacancy by selection having first given consideration to the requirements of section 105 of the Education Act 1989. There must always be more elected than selected parent trustees.

A standard board of trustees' membership includes:
between three and seven parent elected trustees,
the principal of the school,
one staff elected trustee,one student-elected trustee (only in schools with students above Year 9),
co-opted trustees, and up to four trustees appointed by the proprietor (in state integrated schools only).

Boards of trustees must hold elections for parent and staff trustees every three years (triennial election). A board may also decide to adopt a mid-term (as our school has) election cycle where half the parent representatives are elected at a mid-term election (18 months after the triennial election) and the remainder are elected at the triennial election. Elections for student trustees must be held annually in September in schools with students above Year 9.